The overall objective of this project is to compare the metabolism, intracellular distribution and binding of steroids in human normal endometrium and endometrial adenocarcinoma or its precursors. The study of hormonal effects, in vivo and in vitro, on these parameters is also part of this project. Tissue slices and cells in culture (normal endometrium, endometrial adenocarcinoma, breast carcinoma) will be used to study the following parameters: (1) specific activities to enzymes involved in the metabolism of estrogens and androgens, (2) response of enzymatic activities to hormones (e.g., progesterone and progestins), (3) levels of receptor for estradiol and progesterone, (4) hormonal control of these receptor levels, (4) endogenous levels of estrogens and androgens in tissue. In vitro hormonal actions (e.g., influence of progestins on estradiol dehydrogenase and estradion receptors) will be correlated with effects of hormonal treatment of patients with uterine cancer.